The Anatomy of Tigers


| Physical Measurements | Claws | Ears | Eyes | Feet | Fur | Genetics | Tail | Teeth | Whiskers | |


 

 

 

 

 

 

 

 


Physical Measurements:
Weight: Tigers are sexual dimorphic, females are on average 275-400 pounds and males are 400 to 600 pounds. However male tigers can get as big as 800 pounds.
Siberian tigers are the largest tigers and Sumatran tigers tend to be the smallest.
The differences in anatomy between tiger subspecies is NOT genetic, rather it is due to the environment selecting for various characterstics. This is why tiger measurements across subspecies are approximations and the reason for significant overlap.
Length: Depending on the subspecies and the gender, the head-body length of a tiger is about 4 1/2 to 9 feet (1.4-2.8 m). The length of the tail is 3 to 4 feet (90-120 cm).
Shoulder Height: 36-42 inches

Claws:
Tiger claws are retractable and are up to 5 inches in length. They usually are between 3.5 - 4 inches though.
There are five claws (including the dew-claw) on the forefeet, and four claws (no dew claw) on the hindfeet.
Tigers sharpen their claws by scraping them on tree bark. The scratch marks left on trees also serve as territorial markers against other tigers.

Ears:
It's hypothesized what the tiger's white ear spots may enable mothers and cubs to keep track of each other when it's dark1.

Eyes:
Tigers have round pupils and yellow irises (white Bengal tigers have blue irises) (source: 5tigers.org).
An adaptive trait that tigers have is called a tapedum (humans don't have this trait but several other species have this; especially nocturnal animinals). It reflects light back to the retina and causes a tiger's eyes to 'glow' in the dark and is responsible for their strong night vision which is approx. six times better than humans.
Tigers eyes unlike humans, have narrow pupils with a bulge at the center (similar to a discus). A humans pupil in comparison is round. It is thought that tigers do not have good colour vision. This is becuase of a type of cell termed "cones" is not present in tigers' eyes. This does allow them to have more "rod" cells in their eyes allowing them to see better at low light levels (scotopic vision). Feet:
The foot pads vary in size with age.

Fur:
Tiger hair length varies b subspecies and by location on the body.
The tell-tale orange coat with black stripes covers most of the body. However, the stomach is white. Additionally, white tigers do not have stripes on their stomachs as well.
A tiger's black stripes act as camouflage which aides in hunting. The pattern of stripes gives each tiger his/her own distictive appearance.
Due to climatic adaptations, Sumatran tigers have more stripes than the other tiger subspecies.
The Siberian tiger has the fewest stripes likely becuase more stripes in their snowy environment makes them more suseptable to being spotted. It may be that selection through human hunting allowed those tigers whose genes code for fewer stripes to survive since they are less likely to be spotted.
In China, it is said that a tiger's head has stripe marks similar to the Kanji symbol for "wang".
Tigers fur length is ~7 to 20 mm on the back and ~15 to 35 mm on the stomach. The Siberian tiger fur is longer due to its cold climate with its fur ~40 to 60 mm on the back and 70 to 105 mm on the stomach (source for fur length: 5tigers.org).
A tiger's fur density varies based on climate. The Sumatran tiger has ~1,700 to 2,000 hairs/cm2 while the winter coat of the Siberian tiger has as many as 3,000 to 3,300 hairs/cm2 (source for fur density: 5tigers.org).

Genetics:
Tigers have 19N chromosomes (19 pairs; one from the father and one from the mother). This totals to 19x2=38 total chromosomes (source: 5tigers.org). Humans have 23N, which amounts to 46 chromosomes.
Like all animals, mitochondrial DNA is inherited only maternally. This it becuase a mother is the source of an infants mitochondria (which has it's own genetic code).

A tigers phenotype (physical appearance) is a combination of its genotype (genetics) plus the affects of the enviroment. Attributes such as a tiger's stripe pattern, gender, and eye color are completely controlled by its genotype. Body weight, strength etc. is a results of a combination of the genotype and phenotype.

Tail:
Averages around 36 inches in length

Like in all other animals with tails, a tiger's tail is utilyzed in maintaining balance while running/turning/navigating high areas. Along with their face, a tiger's tale can help communicate a tiger's mood. Teeth:
An adult tiger has 30 teeth (adult humans have 28 including the molars).
Like other animal, tigers have incisors, canines, premolars, and molars.
Depending on the type of tooth, the size can vary from > 1 inch to 3 inches (canine teeth are typically the longest)

Whiskers:
Like all other animals, a tiger's whiskers are senstive and are used in sensory perseption. A tiger's whiskers average around 6 inches (15 cm), and are around 1/8 inches (3.0 mm) thick at the base. Male whiskers are typically longer than female's.

This page is in its infancy. Lot more to come in the future.


Copyright © 2000-1 by Sheel Walvekar